1. Our walls are packed tight with Applegate-brand cellulose.
While delivering an R-value of 21 in our 6-inch walls, and an R-value of 13 in our 4-inch walls, the real magic of dense-pack cellulose is how completely it fills the wall cavity. This dense, complete fill means that air infiltration, the primary cause of heat loss, is reduced, and the insulation actually performs up to its theoretical R-value. (Unfortunately, standard fiberglass batt insulation contributes nothing to air sealing and often performs well below its factory insulation rating.)
2. Foam is cool, and effective.
An efficient home makes use of every bit of potential space, including "under the rafters" areas on the second floors of many cottages, but insulating and air-sealing these unusual spaces properly is nearly impossible with traditional means. To meet this challenge, Bellevue Homes uses Icynene spray foam, the industry leader in "open cell" foam. When applied to the roof and other hard-to-reach areas of the home, the foam forms an air-tight barrier. Given how much heat leaves a standard unsealed roof, this air-tight barrier is crucial to maintaining a comfortable temperature at a reasonable price.
Like other foams, Icynene is a petroleum-based product; while it is not perfect from a "green" perspective, we believe that the energy savings it creates more than offsets the energy used to produce it. And unlike other foams, Icynene uses water rather than a CFC as its "blowing agent" (the material used to create the air bubbles in the foam), another plus factor in the product's environmental impact.
3. Fiberglass batts are good for something.
If you are a reader of our blog, you know that we don't favor fiberglass batts, as they don't contribute to air sealing (the first priority in energy efficiency and comfort) and they generally perform well below their laboratory insulation ratings. However, they do perform rather nicely in the role of sound insulation--such as in the picture below, muting the sound from the washing machine and dryer. The first Bellevue Cottage at Oak Park has sound insulation around the utlity room, all bathrooms and all drainage pipes from the second floor.
4. Our insulation contractor, Creative Conservation, really "sweated the details."
Creative Conservation has been the leading insulation contractor in Central Virginia for 3 decades. While quality insulation projects require the right products, proper installation is even more important. Home construction by its very nature creates multitudes of little holes (to pass electric wires, or to vent the exhaust from a gas range), and all of these holes represent potential energy loss if they aren't filled. It may not be glamorous, but filling each of these holes is mission-critical if the home is going to be as energy efficient as it can be.
The picture below is one example of "filling the holes"--an electric wire, a control wire, and a heating duct are running from the conditioned crawl space through the subfloor, and each is sealed with an expanding foam. Just multiply this work by 200+ holes or so...
Below is another image that demonstrates the importance of sweating the details. Were you aware that there are energy-stealing air gaps between wall studs that are nailed together, in this case to support a window opening? If you look closely at the image below, you'll see that the Creative Conservation team has carefully placed caulk along each of these gaps.
Multiple little things adding up to a big overall impact...that's how energy efficiency and greater comfort are achieved in a "smart" home.
